John w



J. W. COASLJR.

APPARATUS FOR CRACKING HYDROCARBONS.

APPLICATION FILED MAY22|1917.

Patented Mar."29, 1921.

. lates in the bottom of the still.

ject is to facilitate the removal of th1s coke,

UNITED STATES rarizlar OFFICE.

aon w. CoAs'r, .13., CF. TULSA,'0KLAH0MA, ASSIGNOR TO THE PROCESS COMPANY, I 015 TULSA, OKLAHOMA, A CORPORATION or MARYLAND.

resident of Tulsa, in the county of Tulsa,

State of Oklahoma, have invented certain new and useful Improvements in Apparatus for Cracking Hydrocarbons, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

1 My invention relates to improvements in apparatus for crackmg hydrocarbons, one

of the objects being toprotect cylindrical cracking stills from the injurious effects of the coke, or carbon, which usually accumu- Another obor carbon from the still.

In the preferred form of the invention, an oscillatory scraping device is arranged within a cracking still and fitted to the bottom thereof. This scraping device ext-ends approximately from one end of the still to the other, and it is preferably operated intermittently so as to stir the contents of the still, at the same time sweeping the coke- -forming substances back and forth on the still bottom. The transmission of heat from the still bottom to the liquid is facilitated by stirring the contents of the still in this manner, and the coke-forming substances are prevented from accumulating in piles on the hottest part of the-still. A saving in fuel is effected,'and the still bottom will not be overheated by the fire to which it-is subjected.

In removing the residue from a cracking still, the liquid portions of the residue are usually pumped from the still, leaving a hard mass of coke, or carbon, adhering to the bottom of the still. It is quite difficult to remove such coke, or carbon, for it is usually firmly incrusted on the bottom of the still. I have discovered that this condition is brought about by a drying process to whichthe coke or carbon is subjected after the liquid-has been removed from the still.

' The still is usually hot enough to dry the coke or carbon before the workman enters the still to remove the same. I have also discovered that the coke. or carbon will not adhere firmly'to the still if it is stirred while undergoing the drying process. In this event, the coke or carbon will be broken up ArrAnATUs FOR CRACKING HYDROCARBONS.

Specification of Letters Patent. Patented Ian 29, 1921 Application filed May 22,

1917. Serial No. 170,149.

into loose flakes, which can be very easily removed fIOHI the still.

Figure I is a longitudinal section of'a cracking still provided with a scraping device embodying the features of my invention.

Fig. II is an enlarged transverse section showing the lower portion of the still and the scraping device mounted therein.

Fig. III is an enlarged fragmentary plan view of the scraping device.

To illustrate the invention, I have shown a large cylindrical cracking still 1 arranged over a heating chamber 2, and provided with a vapor pipe 3. The oscillatory scraping device comprises a frame including three long, rectangular frame members 4:, 5 and 6, separated from each other by fillers 7 (Fig.

' III), and connected together by rivets passing through these fillers. These long, rectangular frame members extend approximately from one end of the still tothe other, and the middle frame member 5 is provided with journals 8 and 9 at the axis of the still. The journal 9 is mounted in a bearing at one end of the still, and the journal 8 extends through a stuffing box 10 at the opposite end. An operating crank 11 is fixed to the journal 10. 12 designates a connecting rod through which movement is transmitted to the crank 11 for the purpose of oscillating the scraping device.

The fillers 7, arranged between the frame members 4, 5 and 6, are positioned to form staggered guideways for the scraping members 13, the latter being loosely mounted in the oscillatory frame and fitted to the bottom of the still. Lugs 14:, formed on the scrapers 13, prevent the scrapers from acciextends approximately from one end of the still .to the other. The scrapers are staggered in such a manner that the scrapers of one row will overlap the paths of the scrapers in the other row.

When the still is in operation, the scraping device is oscillated intermittently to circulate the liquid transversely of the still, thereby facilitating the transmission of heat to the liquid, at the same time breaking up the deposits of cokeforming substance, shifting the latter transversely of the arouate still bottom. When the scraping device is not in motion it preferably occupies the position shown by dotted lines in Fig. II, and a large percentage of the coke-forming substance Will then lie on the elevated scrapers 13, Where it will not interfere with the transmission of heat through the still bottom.

In removing the residue at the end of a run, the free liquid is pumped from the still, and thereafter the carbon or cokeforming substances Will undergo a-drying process, due to the heat in the still. During this drying process the oscillatory scraper is actuated to stir the carbon or coke-forming substance, sweeping it back and forth transversely of the bottom of the still, thereby preventing it from adhering to the still. The loose carbon or coke remaining in the still can be very easily removed.

I claim:

In an apparatus for cracking hydrocarbons, a horizontal cylindrical cracking still,

and an oscillatory scraper comprising an oscillatory frame provided With journals at the horizontal axis of the still, continuous rows of scrapers extending approximately in straight lines from one end of the still to the other, all of said scrapers being slidably mounted in said oscillatory frame and free to drop by gravity so as to yieldingly engage the arcuate bottom of the still, said scrapers being staggered so that the scrapers of one row will overlapithe paths of the scrapers of the other row, and said oscillatory scraping device being free to move transversely of the bottom of the still so as to stir the contents of the still and at the same time sweep the cokeforming substances back and forth on the arcuate still bottom.

In testimony that I claim the foregoing I hereunto aflix my slgnature.

JOHN W. COAST, JR. 

